| 摘要 |
Although metabolic networks have been reconstructed on a genome-scale, the corresponding reconstruction and integration of governing transcriptional regulatory networks has not been fully achieved. Here such an integrated network was constructed for amino acid metabolism in Escherichia coli. Analysis of ChlP-chip and gene expression data for the transcription factors ArgR, Lrp, and TrpR showed that 19/20 amino acid biosynthetic pathways are either directly or indirectly controlled by these regulators. Classifying the regulated genes into three functional categories of transport, biosynthesis, and metabolism leads to elucidation of regulatory motifs constituting the integrated network's basic building blocks. The regulatory logic of these motifs was determined based on the relationships between transcription factor binding and changes in transcript levels in response to exogenous amino acids. Remarkably, the resulting logic shows how amino acids are differentiated as signaling and nutrient molecules. This reveals the overarching regulatory principles of the amino acid stimulon. |
